A typical gas turbine is made up of a compressor, a combustor, and a turbine. Air taken in through an air duct is compressed by the compressor to produce high-temperature, high-pressure compressed air, to which fuel is supplied and the two are combusted in the combustor to obtain high-temperature, high-pressure combustion gas (operating fluid), which is used to drive the turbine, thereby driving a power generator coupled to the turbine.
Such exhaust flues for discharging exhaust gas from gas turbines of this sort may emit low-frequency component noise of a few Hz or less to the outside as the result of resonance in the acoustic field within the gas turbine. Because low-frequency component noise is often at or below the frequencies audible to humans, for example, such noise is rarely directly perceived, but it can indirectly cause rattling in windows and the like in buildings around the plant.
Silencers are one technology used to reduce the possibility of specific low-frequency component noise of this sort from being released to the outside (see Japanese Unexamined Patent Application Publication No. H11-159347A).